protocol Vehicle {
    func startEngine()
    static func vehicleType() -> String
}

class Car: Vehicle {
    func startEngine() {
        print("Car engine started")
    }

    static func vehicleType() -> String {
        return "Car"
    }
}
var myCar: Car = Car()
myCar.startEngine()  // 输出: Car engine started
print(Car.vehicleType())  // 输出: Car
